1. Field of Invention
The present invention relates to an illuminated signage apparatus operable in high ambient and low ambient light environments and by way of example, relates to a signage light module, such as a traffic light module.
2. Identification of Prior Art
LED traffic light modules are currently being used to replace incandescent lamp traffic light modules. The rationale behind the replacement is energy efficiency. A typical incandescent lamp traffic light module consumes about 80 W to 120 W of power when illuminated compared to 20 W to 30 W for an LED traffic light module. Furthermore LED traffic light modules have longer operational life times and require less ongoing maintenance.
Prior Art concerning LED traffic light modules is disclosed in various publications including; Tech Update by E Source, November 1995, pp. 1-16 and Secs. 13.1 to 13.2.2 of E Source Publication, 1994. The LED traffic light module 1 disclosed includes the vertical or horizontal arrangement of at least three round traffic light signals (Red, Yellow, Green) and can also include a protected turn signal (Red Arrow, Green Arrow) (See FIG. 1a, FIG. 1b, FIG. 1c—Prior Art). Each traffic light is comprised of an array of LEDs 5 patterned in a circular or arrow shaped arrangement 4. This Prior Art states the advantages of lower power consumption and longer operational life time compared with incandescent lamp traffic light signals. This Prior Art discloses mounting a plurality of different coloured LEDs on different printed circuit board in various patterns. It should be noted that the three primary traffic signals (Stop, Go, Caution) require three different circular arrays of red, green and yellow LEDs.
U.S. Pat. No. 4,857,920 (Kataoka et. al.) discloses a traffic light signal comprised of two or more semiconductor thin-film EL plates 7, 8 such as green and red one stacked on top of the other. This Prior Art deals with fabricating a single traffic light signal that will produce three different colours depending on whether voltage is applied to either or both thin-film EL elements (See FIG. 2a, FIG. 2b, FIG. 2c, FIG. 2d—Prior Art). This Prior Art states the advantages of lower power consumption, less maintenance and providing all 3 traffic signals (Red, Green, Yellow) in a single lens traffic light. It should be noted that this Prior Art does not appear to disclose a method for informing a colour blind person as to which traffic signal (Stop, Go, Caution) is currently activated.
U.S. Pat. No. 6,054,932 (Gartner et. al.) discloses a single LED traffic light that provides at least three signals (Stop, Go, Caution). This traffic signal comprises the mounting of a plurality of different coloured LEDs 16 mounted on a single printed circuit board 15. The sign comprises 4 concentric (sometimes overlapping) patterns of LEDs; an octagon, a second octagon, a circle and a triangle. (See FIG. 3a, FIG. 3b, FIG. 3c, FIG. 3d—Prior Art). Various combinations of different coloured LEDs 17, 19, 20 are placed in the overlapping areas of the concentric shapes. The different traffic signals, for example; Stop, Go, Caution, are activated and controlled by powering individual LEDs by a suitable power source and switches. This Prior Art states the advantages of providing at least three traffic signals (Stop, Go, Caution) in a single lens traffic light.